Water-thin emulsions with low emulsifier levels

ABSTRACT

The invention relates to a water-thin emulsion comprising a non-phospholipid, non-ethoxylated pseudoemulsifier system, the system having a chemical composition with at least one hydrophobic moiety and at least one polar moiety, the size, shape and/or planar arrangement of the hydrophobic and polar moieties being asymmetrical with respect to each other. The emulsion of the invention is prepared by high-pressure homogenization of a crude oil and water emulsion containing the pseudoemulsifier. The emulsions require little or no traditional emulsifier to maintain stability, and are particularly useful in the preparation of multiple emulsions.

[0001] This application is a continuation and claims benefit of U.S.Ser. No. 09/580,743, filed 26 May 2000 and currently allowed.

FIELD OF THE INVENTION

[0002] The invention relates to cosmetic and pharmaceuticalformulations. More specifically, the invention relates to cosmetic andpharmaceutical formulations containing low levels of emulsifiers.

BACKGROUND OF THE INVENTION

[0003] One of the most common vehicles for cosmetic and pharmaceuticalproducts is the emulsion. Because they are formed by the dispersion ofan oil in water, or water in an oil, they provide great versatility inthe delivery of different types of active ingredients. A single oil andwater formulation can be used to deliver both oil soluble and watersoluble active components, thereby giving the formulation a range ofpotential activity that cannot be matched by a single phase system.

[0004] There are of course limitations to an emulsion vehicle, by virtueof its combination of two inherently incompatible phases. First, anemulsion ordinarily will have a certain amount of innate viscosity;while not necessarily a problem per se, the thickness of the emulsioncan prevent its use in certain types of products or packaging thatrequire a less viscous texture. In addition, in order to maintain astable dispersion, it is ordinarily necessary to add to the formulationssubstantial amounts of emulsion stabilizers and/or emulsifiers. Thenecessity of addition of these materials not only adds cost to the finalproduct, but also has an effect on the quality of the final product, byaffecting the way the emulsion breaks, as well as how it feels on theskin. Added stabilizers can add to the viscosity of the emulsion, andcertain emulsifiers can be irritating to the skin of some users.

[0005] There have been attempts to overcome some of these difficulties.One common approach is the use of high pressure homogenizationtechniques, in which a crude emulsion is passed through a high pressurehomogenizer to yield a relatively thin emulsion. This technique cancontribute to a reduction in the viscosity of the emulsion, and suchemulsions have even been stated as being made with relatively low levelsof emulsifiers. However, the emulsifiers used in these situations areeither of the type that are known to cause irritation, i.e., non-ionicethoxylated emulsifiers, or amphoteric, lecithin-type (phospholipid)emulsifiers, which, being naturally-occurring products, are rathercostly to use. In some cases, these emulsions will still require anaddition of emulsion stabilizers to maintain stability over long periodsof time. There thus continues to be a need for a water-thin emulsionwhich employs minimal levels of a non-irritating emulsifier.

SUMMARY OF THE INVENTION

[0006] The present invention relates to water-thin emulsions prepared byhigh pressure homogenization, in the presence of a non-phospholipid,non-ethoxylated “pseudoemulsifier” having a chemical compositioncomprising at least one hydrophobic moiety, and at least one polarmoiety, the size and/or the planar at least two of one or of both of thetypes of moieties. Although not ordinarily effective for use alone inmaintaining stability of emulsions, the pseudoemulsifiers have beenshown to be highly effective in maintaining the stability of thesewater-thin emulsion, even at very low levels, i.e., less than 1%, and inaddition are very mild and non-irritating to the skin. The water-thinemulsions find a variety of uses as a base for both cosmetic andpharmaceutical products. The invention also provides a method forproducing a water-thin emulsion, comprising mixing oil and water phasesin the presence of the pseudoemulsifier, and subjecting the mixture tohigh pressure homogenization.

BRIEF DESCRIPTION OF THE FIGURES

[0007]FIGS. 1a and 1 b are schematic illustrations of possible differentarrangements of hydrophobic and hydrophilic moieties in thepseudoemulsifiers of the present invention.

[0008]FIG. 2 is a schematic illustration of a surfactin molecule. “AA”represents an amino acid.

DETAILED DESCRIPTION OF THE INVENTION

[0009] The emulsions of the invention have substantially no viscosity,i.e., they exhibit approximately the consistency of water. Theconsistency of the emulsions is primarily due to their processing underhigh pressure homogenization. In brief, the emulsion is prepared, inaccordance with art-recognized techniques, by forming a crude mixture ofthe oil and water phases, in the presence of the appropriateemulsifier(as defined in more detail below), and passing it through ahigh pressure homogenizer for a time sufficient to achieve a stableemulsion. The pressure sufficient to achieve the stable emulsion rangesfrom about 15,000 to about 45,000 psi, or about 1000-3100 bar,preferably about 1300-3000 bar, utilizing one or more passes. Suitablehomogenizers for this purpose are commercially available; these includea microfluidizer, Dee Bee 2000 (BEE International) and Cavitator(FiveStar International). The preferred emulsion is an oil-in-water emulsion.

[0010] While the homogenization process is important in obtaining theappropriate consistency of the emulsion, this aspect alone is notunique. The water-thin emulsions of the present invention utilize a typeof non-ethoxylated, non-phospholipid “pseudoemulsifier”, i.e., acompound or compounds that are not traditionally considered or used asemulsifiers, and/or which, when used alone in a traditional emulsion,are ordinarily not capable of stabilizing the emulsion at the very lowlevels used in the present invention. The type of emulsifier used is anon-ethoxylated, non-phospholipid having a chemical compositioncontaining both hydrophobic moieties and polar (or hydrophilic)moieties, but with an asymmetrical molecular arrangement of themoieties. By “asymmetrical” is meant that the different moieties are ofdifferent sizes (e.g., short chain vs. long chain) and/or shapes (e.g.,straight chain vs. cyclic), and/or are arranged in differentthree-dimensional planes within the composition. Preferably, thepseudoemulsifier is a single compound in which there are at least two ofeither the hydrophilic or hydrophobic moieties. The moieties of a giventype may be the same or different, but are preferably different fromeach other, e.g., a compound will preferably have at least two differenthydrophilic moieties, and/or at least two different hydrophobicmoieties. Hydrophobic moieties can be any primarily hydrocarbon moiety,including, but not limited to, C1-40 linear or branched, substituted orunsubstituted alkyl, cycloalkyl, alkylene, alkaryl, or aryl groups. Thepolar or hydrophilic moieties are, for example, hydroxyl, carboxyl,ester, or amide groups, or hydrocarbon moieties that are highlysubstituted with such polar groups, or combinations thereof. Preferably,the moieties of the same type in a compound are also unequal in size orshape, for example, the hydrophobic moieties can be an alkyl and an arylgroup, or two alkyls of different chain length. It is most preferablethat the pseudoemulsifier have at least one closed, rigid structure,which can be either hydrophilic or hydrophobic in nature, for example,an aliphatic ring with ether, ester or amide linkages, or an aromaticring, the rigid structure being anchored by at least one long-chain,i.e., C8-22, straight or branched hydrophobe or hydrophile, and one ortwo short chain hydrophiles or hydrophobes. Particularly preferredlong-chain moieties are C8-22 fatty acid moieties, such as stearate orpalmitate. Schematic illustrations of some possible differentarrangements of groups in a single compound are shown in FIG. 1. Thepreferred arrangements provide for a broadly dispersed hydrophilicdomain separating the components of the hydrophobic domain. ordinarily,such molecules will not be readily water-soluble or oil-soluble at roomtemperature, but will be readily dispersible in either at highertemperatures.

[0011] In the case in which the emulsifier does not have a rigidstructure per se, it is possible to confer the necessary rigidity bycombining the emulsifier with a polymer having dispersed hydrophilicgroups along the molecule, to form an emulsifier system. Polymers ofthis type will hydrogen-bond within the system, thereby creating thestructure needed to mimic the desirable structure described above.Examples of useful polymers of this type include sugars, such asdisaccharides, e.g., sucrose, lactose, or maltose, and polysaccharides,e.g., cellulose, pectin, xanthan gum, or amylose; or a predominantlyhydrophilic peptide or protein, i.e., ones having a preponderance ofhydrophilic or polar amino acid residues.

[0012] Although it is preferred that the emulsifier components becombined in a single molecule, it is also possible to create a mixtureof compounds, having a similar balance of polar and hydrophobic moietiesand “asymmetry” as described above, i.e., comprising more than onecompound, the compounds used containing a mixture of hydrophobiccomponents and polar or hydrophilic components as described above forthe moieties of a single compound, and which mixture will accomplish thesame result as the use of the single compound. The combination ofcompounds should have an overall average HLB value of between 6 and 8.In one embodiment, the components used can incorporate one hydrophilicand one hydrophobic moiety in a single molecule, for example, a glycerolester, such as polyglyeryl-2-isostearate or a sucrose or glucose ester,such as sucrose stearate or sucrose cocoate, in combination with one ormore compounds which have hydrophilic or hydrophobic moieties. As withthe single compound embodiment, it is preferred that there be at leasttwo hydrophobic moieties or at least two hydrophilic moieties present inthe components employed. In the case in which separate compounds areused to contribute the individual hydrophilic and hydrophobic moieties,however, the requisite structure or rigidity will not be present withoutthe addition of a polymer to tie the components together. Therefore,with separate compounds being used, the addition of a polymer withdisperse hydrophilic groups is important; the polymer will act, asdescribed above, by forming hydrogen bonds with the other components,forming a cohesive system comparable to the single compound system. Whenused, in either the single compound or multiple compound system, thepolymer is employed in an amount of about 0.1 to about 2%. Although themixture per se does not necessarily have an innate asymmetry, exceptperhaps in the different size and/or conformation of the differentcompounds, the combination in situ in the emulsion will self-assembleasymmetrically.

[0013] An example of one embodiment of the single compound structures isa group of anionic emulsifiers of the type that is disclosed in PCTPublication No. WO 91/01970, the contents of which are incorporatedherein by reference. One class of compounds are 2-amidocarbonyl-benzoicacid surfactants having the formula (I): wherein R₁ and R₂ areindependently H or (CH₂)_(n)CH₃, wherein n=8-22, provided that at leastone of R₁ and R₂ is H, wherein M⁺ is a cation selected from the groupconsisting of H, Na, K, NH₄ and derivatives thereof (for example, basicamino acids), Ba, Ca, Mg, Al, Ti, and Zr, and y is an integer of a valuesatisfying the valency of M⁺. Particularly preferred among this class ofsurfactants is a monovalent salt of stearyl amidobenzoic acid,preferably a sodium salt, also known as RM1. This compound and others ofits type are commercially available from Stepan Company, Northfield,Ill. These compounds are known surfactants, which have previously beenreported to form stable oil-in-water emulsions when combined with a lowHLB emulsifier, or a polymeric emulsifier. However, in the present case,these emulsifiers can be used as the sole emulsifier, at very low levels(i.e., as low as 0.25%) to achieve a stable emulsion; this result isparticularly unexpected with an anionic emulsifier alone or at lowlevels. As can readily be seen from the structure depicted above, thesecompounds contain two hydrophobic groups, in the presence of thearomatic ring and the long-chain fatty acid side chain, separated by twohydrophilic groups, namely, the carboxylate and amide portions of themolecule.

[0014] Another example of a compound meeting the requirements outlinedabove is a compound, or a group of structurally-related compounds, allknown as surfactin. This material is naturally occurring, being producedby fermentation of certain strains of Bacillus subtilis, and iscommercially available from Showa Denko, KK, Japan. The structure of themolecule is unusual, being composed of a large hydrophilic ringcontaining seven amino acids bonded to each other by six peptide bondsand an ester bond, and having on either side two short-chainhydrocarbons with free carboxyl groups carrying anionic charges, (thering and carboxyl groups constituting the hydrophilic domain), with ahydrophobic domain comprising a long chain fatty acid residue. Aschematic representation of this type of molecule is seen in FIG. 2. Itwill readily be seen that these molecules possess an asymmetricalarrangement of the hydrophilic and hydrophobic moieties, and also havethe desired rigidity in the presence of the amino acid ring structure.

[0015] As a third example, and one in which there is not a singlecompound, is a combination of xanthan, polyglucomannan, a high HLBemulsifier, and a low HLB emulsifier. Such a combination is availablefrom Uniqema as part of the Arlatone Versaflex Series of highperformance emulsion stabilization systems.

[0016] The water-thin emulsions of the present invention have twodistinct advantages over prior art water-thin emulsions. The firstadvantage is that the pseudoemulsifiers of this type are innately mild,being relatively non-water soluble, and hence, non-reactive with skin,and therefore are less irritating by nature than an ethoxylatedemulsifiers. In addition, the compounds of these systems, even thoughnot ordinarily effective as emulsifiers on their own, have proven to beunusually effective in stabilizing this type of emulsion, therebyimproving even further the mildness of the emulsions by reducing theamount of emulsifier needed. The oil-in water emulsions of the inventionordinarily will contain no more than about 3% total pseudoemulsifier,preferably no more than 2% pseudoemulsifiers, and more preferably, nomore than 0.5% pseudoemulsifier. Because of the unusual properties ofthese pseudoemulsifiers, the emulsion is stable even in the substantialabsence of added emulsion stabilizers. It may, however, be desired tothicken slightly the water-thin emulsion depending on the desired natureof the final product. Therefore, it is possible to add to the emulsion asmall amount of one or more cosmetic powders, not for stabilization, butmerely to modify the viscosity of the product. Examples of types ofpowders that can be used in the present emulsion are silica powders,polymethylmethacrylate, bismuth oxychloride, boron nitride, bariumsulfate, mica, sericite, muscovite, synthetic mica, titanium oxidecoated mica, titanium oxide coated bismuth oxychloride, talc,polyethylene, nylon, polypropylene, acrylates/alkyl acrylatescrosspolymer, acrylamide copolymers, and the like. The powders can beused in an amount of up to about 20%, but ordinarily the powders will beused in small amounts, generally no greater than about 5% of the totalweight of the emulsion, more preferably no greater than 2%. In certainembodiments, the emulsion will contain less than 0.5% by weight ofpowders.

[0017] In order to prepare the water-thin emulsions of the invention,the pseudoemulsifier is combined with any standard oil and wateremulsion components. The aqueous phase may be any cosmeticallyacceptable water based material, such as deionized water, or a floralwater. The oil phase may be any cosmetically or pharmaceuticallyacceptable oil, such an oil being defined for the present purpose as anypharmaceutically or cosmetically acceptable material which issubstantially insoluble in water. As the oils can perform differentfunctions in the composition, the specific choice is dependent on thepurpose for which it is intended. The oils may be volatile ornon-volatile, or a mixture of both. For example, suitable volatile oilsinclude, but are not limited to, both cyclic and linear silicones, suchas octamethylcyclotetrasiloxane and decamethylcyclopentasiloxane; orstraight or branched chain hydrocarbons having from 8-20 carbon atoms,such as decane, dodecane, tridecane, tetradecane, and C8-20isoparaffins.

[0018] Non-volatile oils include, but are not limited to, vegetableoils, such as coconut oil, jojoba oil, corn oil, sunflower oil, palmoil, soybean oil; carboxylic acid esters such as isostearylneopentanoate, cetyl octanoate, cetyl ricinoleate, octyl palmitate,dioctyl malate, coco-dicaprylate/caprate, decyl isostearate, myristylmyristate; animal oils such as lanolin and lanolin derivatives, tallow,mink oil or cholesterol; glyceryl esters, such as glyceryl stearate,glyceryl dioleate, glyceryl distearate, glyceryl linoleate, glycerylmyristate; non-volatile silicones, such as dimethicone, dimethiconol,dimethicone copolyol, phenyl trimethicone, methicone, simethicone; andnonvolatile hydrocarbons, such as isoparaffins, squalane, or petrolatum.

[0019] The ratio of oil phase:water phase in the emulsion is notcritical, and can range from about 10:90 to about 50:50, but is morepreferably from about 30:70 to about 40:60.

[0020] The pseudoemulsifier is ordinarily added to the phase in which itis soluble, or to either phase if it is not soluble in either, alongwith any active components which may be desired in the emulsion, and allcomponents mixed together at low pressure. The mixture is then subjectedto high pressure mixing. By “high pressure” in the present context ismeant a pressure of at least about 15,000 psi, preferably at least about25,000 psi, more preferably about 35,000 psi; generally, a single passthrough the high pressure equipment is adequate to achieve an emulsionof the desired type at higher pressures, although at lower pressures,more than one pass may be required. The amount of pseudoemulsifieremployed is preferably no more than 2%, more preferably no more than 1%.Amounts of as low as 0.25% can be employed, although about 0.5 to about1% is generally preferred. It will be understood that the amount ofpseudoemulsifier and level of pressure can be varied inversely, with ahigher pressure treatment allowing the use of lower levels of emulsifierto produce a stable emulsion, while lower pressure treatments willordinarily require a level of emulsifier at the higher end of theeffective range. The particle size distribution is normally narrow, andvery small, usually in the range of about 50-150 nm, preferably with anaverage size of about 50-100 nm, more preferably about 50 nm.

[0021] An oil-in-water emulsion so prepared can be used as such, or itcan be further used as a base to which an additional water phase,particularly one enriched with active ingredients that may be tootemperature sensitive to be added to the high-temperature pre-mix, canbe added, under low pressure. This approach yields an oil-in-wateremulsion in the form of either a spray, lotion or cream. In thepreparation of such a composition, the oil-in-water emulsion can beadded to the water in an amount ranging from about 90:10 emulsion:waterto 10:90 emulsion:water.

[0022] If desired, the viscosity of the resulting products can beincreased by the addition of water-soluble thickeners such as acrylatescrosspolymers and copolymers, carbomer, guar gum, carageenan,cellulosics, mannan, sulfonic acid polymers, acrylamide copolymer,xanthan gum and the like. Preferably, the amount of thickener rangesbetween about 0.01 to about 1%, preferably no more than about 0.5%.

[0023] In a particularly preferred embodiment, the water-thin emulsionis added to a water-in-oil emulsion, so as to prepare a multiple phaseemulsion. This type of emulsion is valuable for a number of reasons.First, it provides a means for incorporating actives in the same vehiclewhich would not ordinarily be compatible in the same phase, byincorporating them in different phases. It also is a useful vehicle fordelayed release of actives on and into the skin, by virtue of thenecessity of passing through the multiple phases. Despite their clearvalue, however, such emulsions are not frequently employed, as theadditional phase introduces further problems with stability, andtherefore, they frequently require the use of large quantities ofemulsifiers and/or emulsion stabilizers. It has now been found,unexpectedly, that the water-thin emulsion can provide a basis for thepreparation of a multiple emulsion, serving as the outer water phase,without the need for large quantities of emulsifiers. In suchpreparation, the premade water-thin emulsion serves as the water phase,and is mixed, under normal, low-pressure conditions, with a premadestandard water-in-oil emulsion. The two emulsions are preferablycombined in a ratio of about 80 water-thin emulsion:20 water-in-oilemulsion up to 50:50 water-thin:water-in-oil, to yield a stable multipleemulsion. Surprisingly, these multiple emulsions can be prepared with nomore than 2% emulsifiers, and preferably no more than about 1.5%emulsifiers total in the multiple emulsion.

[0024] Even more unexpectedly, the multiple emulsions can be preparedwith an even number of phases, e.g., four phases, rather than thestandard uneven number ordinarily found in multiple emulsions, such aswater-in-oil-in-water. This is made possible by the small droplet sizeof the oils in the water-thin emulsion, which essentially presentsitself as water to a standard emulsion, and is therefore readilyincorporated without the addition of large amounts of emulsifiers.

[0025] Generally speaking, the multiple emulsion can be prepared withlittle or no “traditional” emulsifier, a traditional emulsifiers beingone which, unlike the pseudoemulsifiers, are capable of stabilizingemulsions on their own, even at relatively low levels. When combinedwith a water-thin oil-in-water emulsion to make the multiple emulsion,the multiple emulsion may employ small amounts of a traditionaloil-in-water emulsifier. Examples of useful oil-in-water emulsifiersinclude, but are not limited to, sorbitol derivatives, such as sorbitanmonolaurate and polysorbate 20; ethoxylated alcohols such as laureth-23,ethoxylated fatty acids such as PEG-1000 stearate; amidoaminederivatives such as stearamidoethyl diethylamine; sulfate esters such assodium lauryl sulfate; phosphate esters such as DEA cetyl phosphate;fatty acid amine salts such as TEA stearate; and mixtures thereof.Additional examples can be found in McCutcheon's Emulsifiers andDetergents, 2000, the contents of which are incorporated herein byreference. If used, this type of emulsifier is incorporated inquantities of no more than about 2% by weight of the multiple emulsion,preferably no more than 1%, and more preferably, no more than about0.5%. Stabilizers or thickeners, if used at all, can be employed asdescribed for the water-thin emulsion alone.

[0026] The compositions of the invention can be used for any cosmetic orpharmaceutical purpose in which an standard or multiple emulsion isnormally useful. For cosmetic purposes, the emulsions can be used inmakeup products as well as skin-care products. In such cases, it may bedesirable to incorporate into the emulsion additional components usuallyassociated with the desired cosmetic uses, such as additionalpreservatives, fragrances, emollients, antiseptics, antiinflammatories,antibacterials, stabilizers, sunscreens, antioxidants, vitamins,pigments, dyes, humectants, and propellants, as well as other classes ofmaterials the presence of which in the compositions may be cosmetically,medicinally, or otherwise desired. Such components can be found in theCTFA International Cosmetics Ingredients Dictionary, supra.

[0027] For pharmaceutical or therapeutic cosmetic use, the emulsion canincorporate any variety of topically applied therapeutic agents,particularly those that will benefit from a delayed release of activeagents. Examples include, but are not limited to, agents for theeradication of age spots, keratoses and wrinkles, analgesics,anesthetics, anti-acne agents, antibacterials, antiyeast agents,antifungal agents, antiviral agents, antidandruff agents, antidermatitisagents, antipruritic agents, antiemetics, antimotion sickness agents,anti-inflammatory agents, antihyperkeratolytic agents, anti-dry skinagents, antiperspirants, antipsoriatic agents, antiseborrheic agents,hair conditioners and hair treatment agents, antiaging agents,antiwrinkle agents, antiasthmatic agents and bronchodilators, sunscreenagents, antihistamine agents, skin lightening agents, depigmentingagents, vitamins, corticosteroids, self-tanning agents, hormones,retinoids, such as retinoic acid, 13-cis retinoic acid, and retinol,topical cardiovascular agents, clotrimazole, ketoconazole, miconozole,griseofulvin, hydroxyzine, diphenhydramine, pramoxine, lidocaine,procaine, mepivacaine, monobenzone, erythromycin, tetracycline,clindamycin, meclocyline, hydroquinone, minocycline, naproxen,ibuprofen, theophylline, cromolyn, albuterol, topical steroids such ashydrocortisone, hydrocortisone 21-acetate, hydrocortisone 17-valerate,and hydrocortisone 17-butyrate, betamethasone valerate, betamethasonediproprionate, triamcinolone acetonide, fluocinonide, clobetasol,proprionate, benzoyl peroxide, crotamiton, propranolol, promethazine,vitamin A palmitate, vitamin E acetate and mixtures thereof.

[0028] The invention is further illustrated by the followingnon-limiting examples.

EXAMPLES Example 1

[0029] This example illustrates the preparation of an oil-in-wateremulsion of the invention. Weight % Material Batch 1 Batch 2 Batch 3Water Phase Deionized water 65.25 64.70 62.50 Disodium EDTA 0.10 0.100.10 Methyl paraben 0.05 0.05 0.05 Butylene glycol 3.00 3.00 3.00phenoxyethanol 0.40 0.40 0.40 Oil Phase Behenyl alcohol 0.75 0.75 0.75Pentaerythrityl tetraoctanoate 30.00 30.00 — Stepan RM1 0.50 1.00 0.50C12-15 alkyl benzoate — — 30.00

[0030] The water phase materials are heated to 85-90° C. The oil phasematerials are heated to 85° C. The oil phase materials are added to thewater phase materials using a Silverson (low pressure) homogenizer. Thebatch is then run through a DEE/BEE 2000 homogenizer at 40,000 psi, andcooled to room temperature in the machine.

Example 2

[0031] This example illustrates the use of the emulsions prepared abovein creating a variety of low emulsifier skin care products. A. Lowemulsifier creme Material Weight % Phase I Deionized Water 19.00acrylamide copolymer (1.5%) 10.00 Glycerine 10.00 antiinflammatorypolysaccharide 1.00 Phase II Batch 3 39.60 Acrylates/C10-30 alkylacrylates Crosspolymer (2%) 20.00 triethanolamine 0.40

[0032] Phase I and Phase II components are separately premixed bypropeller mixing. The two phases are then mixed to homogeneity with apropeller or paddle. Material Weight % B. Low emulsifier milk lotionsBatch 2 97.00 99.00 Magnesium ascorbyl phosphate 3.00 — N-acetylglucosamine — 1.00 C. Low emulsifier cleanser Phase I Deionized water18.70 methyl paraben 0.10 Phase II glycerine 10.00 Phase III Acrylamidecopolymer (1.5%) 10.00 Phase IV Acrylates/C10-30 alkyl acrylates 20.00crosspolymer (2%) Phase V Batch 2 39.60 Phase VI triethanolamine 0.40deionized water 0.50 Phase VII Germall 115 0.20 deionized water 0.50

[0033] Phase I materials are heated to 75° C., and cooled to roomtemperature. Phases II, III, and IV are added to Phase I under propelleragitation. After addition of Phase IV, viscosity increases, requiring achange to a paddle. Phases V, VI and VII are then added to the mixture,and mixed to homogeneity.

Example 3

[0034] This example illustrates the process of preparing a multipleemulsion according to the invention. A. A water-in-oil phase is preparedas follows: Material Weight % Phase I Cyclomethicone/dimethicone 5.00Phenyltrimethicone 5.00 Dimethicone/copolyol crosspolymer 7.00Cyclomethicone 1.00 Dimethicone 8.00 Phase II Xanthan gum 0.20 Deionizedwater 64.30 Sodium chloride 1.00 Butylene glycol 5.00 Parabens 0.50

[0035] The oil phase ingredients are combined together, and the waterphase ingredients are combined together. The water phase is then slowlyadded to the oil phase, and homogenized until uniform. B. Water-thin,low emulsifier emulsion Material Weight % Phase I deionized water 32.50Arlatone Versaflex High 1.00 Performance Emulsion Stabilizer* Phase IIDeionized water 32.05 Methyl paraben 0.20 Butylene glycol 3.00Phenoxyethanol 0.40 Phase III Behenyl alcohol 0.75 Pentaerythrityltetraethylhexanoate 30.00 Beta-carotene 0.10

[0036] In Phase I, the emulsifier is added to water at 80° C. Phase IIingredients are added to Phase I at 80° C. Phase III ingredients arecombined and then homomixed with Phase I and II ingredients at greaterthan 10,000 rpm for 5 minutes. The combined components are then passedthrough a microfluidizer at 16,000 psi three times to achieve awater-thin emulsion. C. Multiple emulsion Material Weight % Polysorbate20 0.20 Carbopol 1.00 O/W emulsion from B. 78.80 W/O emulsion from A.20.00

[0037] The O/W emulsion is combined with the Carbopol using staticmixing. Polysorbate 20 is then added. The W/O emulsion is slowly addedto the O/W phase utilizing static mixing. When the addition is complete,the mixing is continued for about 5 minutes until the multiple emulsionis uniform.

[0038] Similar positive results are obtained in preparing a multipleemulsion as described above, utilizing RM1 as the pseudoemulsifier, andcombining the O/W emulsion and the W/O emulsion in a ratio of 60:40.

What is claimed is:
 1. A water-thin emulsion comprising a non-phospholipid, non-ethoxylated pseudoemulsifier system, the system having a chemical composition with at least one hydrophobic moiety and at least one polar moiety, the size, shape and/or planar arrangement of the hydrophobic and polar moieties being asymmetrical with respect to each other.
 2. The emulsion of claim 1 in which the system is a single compound having at least two hydrophobic moieties, at least two polar moieties, or at least two of both hydrophobic and polar moieties.
 3. The emulsion of claim 1 in which the system is a mixture of compounds comprising at least two hydrophobic moieties, at least two polar moieties, or at least two of both hydrophobic and polar moieties.
 4. The emulsion of claim 1 which is substantially free of phospholipid and ethoxylated emulsifiers.
 5. The emulsion of claim 1 which contains no more than 2% by weight of the pseudoemulsifier.
 6. The emulsion of claim 1 which contains no more than 1% of the pseudoemulsifier.
 7. The emulsion of claim 1 in which the pseudoemulsifier is a 2-amidocarbonyl-benzoic acid compound having the formula (I) wherein R₁ and R₂ are independently H or (CH₂)_(n)CH₃, wherein n=8-22, provided that at least one of R₁ and R₂ is H, wherein M⁺ is a cation selected from the group consisting of H, Na, K, NH₄ and derivatives thereof (for example, basic amino acids), Ba, Ca, Mg, Al, Ti, and Zr, and y is an integer of a value satisfying the valency of M⁺.
 8. The emulsion of claim 7 in which the pseudoemulsifier is a monovalent salt of stearyl amidobenzoic acid.
 9. The emulsion of claim 1 in which the pseudoemulsifier is surfactin.
 10. The emulsion of claim 1 in which the system also comprises a polymer.
 11. The emulsion of claim 10 in which the polymer comprises dispersed hydrophilic moieties.
 12. The emulsion of claim 11 in which the polymer is selected from the group consisting of disaccharides, polysaccharides, or a predominantly hydrophilic peptide or protein.
 13. The emulsion of claim 3 in which the system comprises at least one compound selected from the group consisting of glycerol esters, sucrose esters and glucose esters.
 14. The emulsion of claim 13 in which the system comprises both a glycerol ester and a sucrose or glucose ester.
 15. The emulsion of claim 14 in which the system also comprises a polymer.
 16. The emulsion of claim 15 in which the polymer is selected from the group consisting of disaccharides, polysaccharides, and predominantly hydrophilic proteins or peptides.
 17. The emulsion of claim 3 in which the system comprises xanthan, polyglucomannan, a high HLB emulsifier, and a low HLB emulsifier.
 18. The emulsion of claim 13 in which the system comprises xanthan, polyglucomannan, a high HLB emulsifier, and a low HLB emulsifier.
 19. A water-thin oil-in-water emulsion comprising a non-phospholipid, non-ethoxylated pseudoemulsifier system, the system having a chemical composition with at least two hydrophobic moieties, at least two polar moieties, or at least two of both hydrophobic and polar moieties, the size, shape and/or planar arrangement of the hydrophobic and polar moieties being asymmetrical with respect to each other, each polar moiety being of a different size or shape than the other polar moiety if present, and each hydrophobic moiety being of different size or shape than the other if present.
 20. The emulsion of claim 19 in which the hydrophobic moieties are of different chain lengths.
 21. The emulsion of claim 19 in which at least one of the moieties has a closed ring structure.
 22. The emulsion of claim 19 in which at least one of the moieties is a long straight-chain moiety.
 23. The emulsion of claim 19 in which at least one of the moieties has a closed ring structure, and one of the moieties is a long, straight chain moiety.
 24. The emulsion of claim 23 in which the system comprises a hydrophobic closed ring structure, and a long chain hydrophobe, separated from each other by a hydrophilic moiety.
 25. The emulsion of claim 24 in which the hydrophilic moiety is selected from the group consisting of hydroxyl, amide, ester, or carboxyl moieties, hydrocarbons chains substituted with hydroxyl, amide, ester, or carboxyl moieties, and combinations thereof.
 26. The emulsion of claim 23 in which the system comprises a hydrophilic closed ring structure, at least one carboxyl moiety, and a long chain fatty acid moiety.
 27. The emulsion of claim 19 in which the emulsifier system comprises more than one compound.
 28. The emulsion of claim 27 in which at least one of the compounds comprises a long, straight-chain hydrocarbon moiety.
 29. The emulsion of claim 28 in which at least one of the compounds comprises a hydrophilic moiety selected from the group consisting of hydroxyl, amide, ester, or carboxyl moieties, hydrocarbons chains substituted with hydroxyl, amide, ester, or carboxyl moieties, and combinations thereof.
 30. The emulsion of claim 29 in which the system further comprises a polymer selected from the group consisting of disaccharides, polysaccharides, and predominantly hydrophilic proteins or peptides.
 31. A water-thin oil-in-water emulsion prepared by processing the combined oil and water phases comprising a non-phospholipid, non-ethoxylated pseudoemulsifier system, the system having a chemical composition with at least one hydrophobic moiety and at least one polar moiety, the size, shape and/or planar arrangement of the hydrophobic and polar moieties being asymmetrical with respect to each other, through a high pressure homogenizer at a pressure of at least about 15,000 psi.
 32. The emulsion of claim 31 in which the system is a single compound having at least two hydrophobic moieties, at least two polar moieties, or at least two of both hydrophobic and polar moieties.
 33. The emulsion of claim 31 in which the system is a mixture of compounds comprising at least two hydrophobic moieties, at least two polar moieties, or at least two of both hydrophobic and polar moieties.
 34. A multiple emulsion comprising the emulsion of claim
 1. 35. A multiple emulsion incorporating the emulsion of claim
 6. 36. A multiple emulsion incorporating the emulsion of claim
 19. 37. A multiple emulsion incorporating the emulsion of claim
 27. 38. The emulsion of claim 33 that comprises no greater than 1% of traditional emulsifier.
 39. The emulsion of claim 35 that comprises no greater than 1% of traditional emulsifier.
 40. The emulsion of claim 36 that comprises no greater than 1% of traditional emulsifier.
 41. The emulsion of claim 37 that comprises no greater than 1% of traditional emulsifier.
 42. A multiple emulsion prepared by combining a water-in-oil emulsion with the emulsion of claim 1, and mixing to substantial homogeneity.
 43. A method of making a water-thin, oil-in-water emulsion comprising processing the combined oil and water phases comprising a non-phospholipid, non-ethoxylated pseudoemulsifier system, the system having a chemical composition with at least one hydrophobic moiety and at least one polar moiety, the size, shape and/or planar arrangement of the hydrophobic and polar moieties being asymmetrical with respect to each other, through a high pressure homogenizer at a pressure of at least about 15,000 psi. 